As promised here's a look at my setup. 20D with 420EX in portrait (to capture those loooong splashes). Home made lightbox (sm version) converted to splash guard

and as much light as I can muster besides the flash (need more). Discovered FP Mode again (setting the flash for high speed synch), which lets me get beyond 1/250s but I need more speed.

Anyway here's what it looks like...

A steady drip is provided from the ah, er, drip bag mounted above by means of control valve. If you get into the rythym you can hit most of the drops.

Not so fancy as a dual IR photogate hooked up to some fancy smansy flash controller but definitely not as expensive either.
